The exhaust gas, which develops in two-stroke engines, should be reduced. At the same time, the structural size of the two-stroke engine should become less. In two-stroke engines, the exhaust gas escapes from the outlet while fresh air/fuel mixture already flows into the combustion chamber. Here, it must be prevented that fresh air/fuel mixture leaves the combustion chamber through the outlet because, in this way, the HC values in the exhaust gas increase. For this reason, the transfer channels, through which the fresh mixture flows, should open as late as possible after the opening of the outlet from the combustion chamber. However, by displacing the transfer channels in the direction of the crankcase, the structural size of the engine is increased. The transfer channels must furthermore be dimensioned to be adequately large and to be open sufficiently long in order to ensure the supply of an adequate fresh mixture quantity to the combustion chamber. For these reasons, the constructive arrangement of the transfer channels on the cylinder is greatly reduced.
From U.S. Pat. No. 6,662,765, it is known to advance store exhaust gas in a transfer channel. For this purpose, the transfer channel is closed to the crankcase while exhaust gas flows into the transfer channel from the combustion chamber end. The inflow of air/fuel mixture into the combustion chamber is to be delayed by the increased pressure level in the transfer channel caused by the exhaust gas. It has, however, been shown that an adequate delay cannot be achieved with this arrangement because the pressure in the combustion chamber does not propagate adequately into the transfer channels and no exhaust-gas flow into the transfer channels takes place.